As lighting for color photos, we can use daylight coming from the window or direct sunlight, if the darker side of the photographed object is lightened with a white background. However, in such cases, due to the changing light, it is difficult to determine the exposure time. Side sunlight gives a very plastic lighting, quite soft though. Flower shadows, curtains or window frames can be used to enliven the background under certain conditions, however, we may be surprised, how fast the shadows move - minute by minute. Using a reflector, which the amateur sometimes has at his disposal and appropriate reflective screens we can achieve the same results. However, if we use an incandescent lamp, the exposure time will be longer. Photo lamps are useful, but one bulb is enough 200 W, which will brighten the shadow side of the subject. Reflective screens in mild lighting are not necessary, as, for example, a cluster of individual leaves can only be reproduced as contours, for which we need significant shadows. Therefore, do not place the flash too close to the camera. You should also protect yourself from this, so that stray light from the flash or reflected from the reflector does not fall on the lens. Even then, when there are no reflections on the photosensitive material, in any case, the stray light will weaken the contrast of the image as well as reduce the quality of reproduced colors. Therefore, you should basically work with a good sunshade, using which only the light that draws the image will fall into the lens. The lamp should be positioned in relation to the lens, so that the resulting increase in exposure time can be compensated for, which is always necessary, if the focus distance was previously shorter.
We now turn to the difficult issue of evaluating the exposure time, which in the case of colored materials is quite a critical issue as a result of a rather narrow range of exposures. Who has a photoelectric light meter, should do this for close up shots: in front of the flowers, a white sheet of paper of approx. A4 and then measures the amount of light reflected from a distance of approx. 40 cm. We can also hold an instrument - preferably a luxmeter - in front of the flowers in front of the camera. In both cases, we cannot use the measurement values obtained directly, but only they can be used as certain factors in determining the correct exposure time obtained on the samples. In special conditions, the instrument can also be calibrated for close-up photos. For tests, we can use black and white material, taking into account the difference in its sensitivity. Be careful when using the above measurement methodology, especially with small flowers, so that the instrument is not too strongly affected by the light reflected from the background. Otherwise, the same flowers will look completely different on a white background than on a dark one.
In general, we should limit the influence of the background, however, they should be taken into account, especially with reversible photos. The exposure can be changed by 50 do 100%, however, light flowers need less exposure than dark ones. If we already have a lot of experience, we must carefully record the shooting conditions, and for photos with reversible materials, regardless of the use of a light meter, for safety, do them several times, at different exposure times.